Averted Vision Illusion?

[Sunshine]

How and why? many times I have used averted vision with some success especially when trying to find a faint object like a barely visible star but tonight i noticed another phenomenon which totally contradicts averted vision.

With the sun just below the horizon Arcturus was just coming into view, the only star I could/couldn't see, wait a minute it was just there! 👀 hold on,  when looking right at it I could see it but when I looked off to the side

a little it disappeared proper, poof! just gone. How could this be? this flies in the face of averted vision does it not? if Arcturus just completely disappeared to a degree that I completely lost it for a few seconds even after I

retrained my sight directly at it then explain averted vision. It was fascinating to see Arcturus completely disappear when I looked slightly away, so much so that I had to scan the area for it again even though It was clearly

there, the disappearing star? or maybe I had too much grown up grape juice with dinner.

Edited July 26, 2022 by Sunshine

[Zeta Reticulan]

I'm guessing too much grape juice.

[Ouroboros]

Averted  vision works when the sky is dark and the object is faint. You imply that the sky was still quite bright.

You can only begin to see a bright star when it is brighter than the background sky.  As you probably know It’s to do with the fact that the central region of the eye (the fovea) contains cone cells which are sensitive to bright light and colour. The rest of the retina contains more sensitive rod cells, not sensitive to colour.

I have seen what you describe many times when trying to spot Venus in the twilight sky.